Electrophysiological and anatomical studies are proposed to investigate the effects of artificial strabismus on the cat visual system. Possible differential effects of convergent and divergent strabismus on the receptive field properties of single neurons in the visual cortex and lateral geniculate nucleus will be investigated. Operations will be performed at different ages to determine if there is a critical period. The anatomical basis of strabismus amblyopia will be investigated. Behavioral studies will be performed to determine if some cats are alternators while others are suppressors. Finally, the duration of abnormal eye alignment which produces changes in the visual system will be investigated. The results of this work should advance our understanding of the effects of strabismus on the visual system.